REGULATION OF THE EXPRESSION OF NMDA RECEPTOR SUBUNITS IN RAT CEREBELLAR GRANULE CELLS - EFFECT OF CHRONIC K-INDUCED DEPOLARIZATION AND NMDA EXPOSURE()
A. Resink et al., REGULATION OF THE EXPRESSION OF NMDA RECEPTOR SUBUNITS IN RAT CEREBELLAR GRANULE CELLS - EFFECT OF CHRONIC K-INDUCED DEPOLARIZATION AND NMDA EXPOSURE(), Journal of neurochemistry, 64(2), 1995, pp. 558-565
The influence of K+-induced membrane depolarization and NMDA treatment
on the regulation of NMDA receptor subunit (NR) expression was invest
igated during the development of granule cells in culture, as a follow
up of previous work on NMDA receptor activity. In spite of the increas
e in NMDA receptor activity elicited by these treatments (K25 or K10 NMDA cultures), the main developmental changes in receptor mRNA level
s were similar to those in untreated cells (K10) (a threefold increase
in total NMDA receptor mRNA, quantitative dominance of NR1 mRNA, late
expression of NR2C, and virtual absence of NR2D). However, high K+ an
d NMDA treatment resulted in a greater increase of NR2A mRNA levels an
d a retardation in the developmental changes in the relative amounts o
f NR2B and NR2C mRNAs. The correspondence between NMDA receptor activi
ty and the amount of NR1 and NR2A subunit proteins was excellent, the
rank order being K25 > K10 + NMDA > K10 at 9 days in vitro. Because th
e increase in subunit mRNA was not always paralleled by an increase in
subunit protein, the control of NMDA receptor expression involves cri
tically, in addition to gene transcription, regulation of translationa
l and/or posttranslational events.